In Kish U.S. Pat. No. 4,114,656, a hose assembly for use in automotive air conditioning systems, is disclosed, the assembly consisting of a hose, a shell crimped to the end of the hose, and a fitting.
The hose is a standard type of hose, made for example, of seamless oil-resistant synthetic rubber. The shell is made from a thin-walled tube of deep drawing steel, aluminum and/or brass, which covers an end portion of the hose and is crimped to the hose. The fitting is a tube or nipple made of welded steel, aluminum and/or brass tubing and extends through a hole in the shell and into that end portion of the hose which is covered by the shell.
The portion of the fitting which extends into the hose is provided with a series of longitudinally or axially spaced circumferential or annular ridges, ribs or barbs which project from the outer surface of the fitting. For the purpose of limiting the extent of entry of the fitting into the hose, the fitting is upset or formed to provide an annular bead which provides a shoulder which engages with the end of the hose.
Due to the fact that the fitting is provided with the aforesaid annular ridges, ribs or barbs which are of slightly larger external diameter than the internal diameter of the hose, considerable force must be exercised in inserting the fitting into the hose, a laborious and time-consuming operation in assembling the hose and fitting.